There are many instances in which vehicle owners will take an automobile or other vehicle into a mechanic's shop, complaining about leakage of an oily liquid out of the vehicle's transmission. But when a mechanic disconnects and then lowers the transmission for a close inspection, it is sometimes discovered that a major part of the problem is not the transmission. Instead, the mechanic may determine that the sealing area at the rear of the engine's crankshaft has become so worn that the oil seal that wipes against the rotating crankshaft is no longer able to contain the engine's lubricating oil. The engine oil seeps past the "full circle" seal where the oil can contaminate and/or render ineffective the vehicle's clutch, etc; and, of course, when oil leaks out of an engine, it is not present to perform its intended function of lubricating the engine. Furthermore, leakage of engine oil is clearly not good for the environment; and examination of many drive-through lanes of banks and fast-food resturants will often reveal a build-up of oil that testified to the fact that many vehicles have an oil leakage problem. Financially, the repair of an engine or its crankshaft is usually more expensive than simply repairing a clutch or transmission, because so many things have to be removed from the vehicle, fixed or replaced, and then reinstalled. It would naturally be desirable if some way could be found to repair the cylindrical sealing surface on a crankshaft (to eliminate any groove) without resorting to the traditional multi-step repair technique. Such a repair technique typically involves removing the engine from a vehicle, removing the crankshaft from its engine, welding a bead of material around the worn area (to replenish the metal that has been worn away), and grinding the welded material down until a fresh, smooth cylindrical surface with a specified diameter has once again been obtained--a bearing surface against which a new rotary seal can be effective.
Another factor must be remembered if a mechanic decides to seriously go into the business of repairing crankshafts, namely, there is no universal standard that is observed by all engine manufacturers as to size and shape of their engines or their respective crankshafts. While it is conventional for all manufacturers to provide an axial recess in the rear end of the crankshaft, the size and shape of that recess will vary among manufacturers from, say, about 1/2 inch to about 2 inches for the diameter, and from, say, 0.125 inch to about 1.5 inches for the depth of the recess. If a mechanic expects to take on the repair of more than one type or brand of engine, it is conceivable that many very specialized tools might be required, some of which might be used only rarely. And it can become very expensive for a mechanic to keep in inventory one of every tool that is offered by distributors and tool jobbers, just in case the day comes along when a particular tool is needed. In fact, auto mechanics who are not prudent can rather quickly find themselves "long" on tools and "short" on cash. It would be beneficial, therefore, if there were a way to provide a tool assembly with a variety of replaceable inserts, each of which could be sized to fit a particular crankshaft, and the sum of which could be effective in the repair of essentially all of the myriad number of crankshafts that a modern mechanic can be expected to encounter.
While the repair of a worn crankshaft without welding it and then grinding the weld material down a smooth surface would be an advance in the art of engine repair, it would be much more desirable to be able to accomplish a repair job without removing an engine from an automobile or the like. Of course, dropping a transmission or moving it somewhat toward the rear can leave the rear end of an engine (and the rear end of the crank shaft) exposed; but being able to see a part that needs repair does not necessarily mean that there is always enough space for a mechanic to be able to do any work to fix a problem. It follows, therefore, that there has been a need for an apparatus and method of being able to quickly and easily repair the worn surfaces of crankshafts, and it is an object of this invention to meet this need.
The very limited space that is available in and under an automobile for accomplishing engine repairs is a major factor to be considered as background for this invention. But it is not the only factor. Indeed, if an engine had already been removed from a vehicle and were now in a shop or factory where it was undergoing inspection and repair, the availabiity of ample working space around the engine would not negate the advantageous use of the tools that are to be described herein. So if this disclosure seems to include unusual emphasis about the cramped working conditions around an engine that is still mounted in a vehicle, it should be remembered that those cramped working conditions have heretofore ruled out any alternative technique for accomplishing repairs. But the possibility of having plenty of working room around an engine should not distract from the fact that the tools that are to be described herein will eliminate the need to tear apart an engine in order to fix something that can be fixed in an alternative--and much quicker and cheaper--manner.
It may accurately be said that it is an object of this invention to accomplish crankshaft repairs while an engine is still mounted in a normal manner in the vehicle, as well as when the engine has been removed for rebuilding and/or more comfortable work.
One more object is to provide a tool assembly that has a "family" of inserts or adaptors, each of which is sized to mate with a selected one of the variety of crankshafts that are extant in today's marketplace--where crankshafts are made in many countries by many different manufacturers who have different philosophies about how mechanical things should be designed and built.
These and other objects will be apparent from a careful reading of the specification and the claims that follow, as well as reference to the several figures of the drawing that are provided herewith.